1. Field of the Invention
The invention relates to an optical scanning apparatus for optical scan that oscillates at least partially an oscillating body having a reflective mirror portion, to thereby modulate a direction in which the reflective mirror portion causes incident light thereon to be reflected off, and more particularly to techniques of enhancing the geometrical property of an elastically deformable portion of the oscillating body.
2. Description of the Related Art
Conventionally, optical scanning apparatuses for use in image forming apparatuses such as laser printers and projectors each scanning laser light for projecting an image are known. Typical types of such optical scanning apparatuses include a unidirectional rotary type represented by a polygon mirror, and an oscillatory type represented by a galvano mirror. The oscillatory type of optical scanning apparatus has been said that it can easily accomplish downsizing, reduction in weight, and reduction in cost, when compared with the unidirectional rotary type of optical scanning apparatus.
One example of conventional optical scanning apparatus of an oscillatory type is such an optical scanning apparatus for optical scan that oscillates at least partially an oscillating body having a reflective mirror portion, to thereby modulate a direction in which the reflective mirror portion causes incident light thereon to be reflected off.
In this example of conventional apparatus, the oscillating body is constructed to include: a reflective mirror portion; a fixed frame portion; and an elastically deformable portion coupled with both the reflective mirror portion and the fixed frame portion. This example of conventional apparatus is constructed to further include an actuator which excites the elastically deformable portion to generate a torsional oscillation.